Cryptosporidium parvum and Cryptosporidium hominis isolates from human immunodeficiency virus-infected patients, cattle, and wild ruminants were characterized by PCR and DNA sequencing analysis of the 60-kDa glycoprotein gene. Seven alleles were identified, three corresponding to C. hominis and four corresponding to C. parvum. One new allele was found (IId), and one (IIb) had only been found in Portugal. Isolates from cattle and wild ruminants clustered in two alleles. In contrast, human isolates clustered in seven alleles, showing extensive allelic diversity.

To investigate the transmission of cryptosporidiosis in Portugal, Cryptosporidium hominis and Cryptosporidium parvum from HIV-infected patients, cattle, and wild ruminants were characterized by sequence analysis of the 60-kDa glycoprotein (GP60) gene. Fourteen subtypes within nine subtype families were identified, and three of the subtype families (If, IIb, and IId) were restricted or largely limited to Portugal. Parasites from cattle from various regions in Portugal and wild ruminants in Lisbon showed limited genetic heterogeneity (only two subtype families). All wild ruminants had the same subtype, which was also the predominant subtype in cattle all over Portugal and was found in nine HIV-infected patients in Lisbon. Two other C. parvum subtypes were only restricted to limited locations. In contrast, human parasites displayed 13 subtypes in nine subtype families, with most of the infections caused by parasites in Ib, IIa, IIc, and IId families. Two of the C. parvum subtype families (IIc and IIb) had only been found in humans. The high overall parasite diversity and high percentage of C. hominis infections attributable to Ib and C. parvum infections to IId represent unique characteristics of Cryptosporidium transmission in humans in Portugal.

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Onchocercosis is a newly recognized disease in dogs that has been reported with higher frequency in Europe and in the United States. We report a case of a 3-year-old male mongrel stray dog from the Algarve region (South Portugal) who had a retrobulbar granuloma containing a filaroid nematode of the genus Onchocerca. A gravid adult female parasite was embedded in a granulomatous inflammation adjacent to the sclera beyond the retina. The parasite was 191 to 267 mum in diameter (mean = 225 mum), surrounded by a cuticule and owing a uterus that was filled with small unsheated microfilariae. The cuticule consisted of two separated layers in longitudinal sections. The external layer had cuticular ridges and the internal layer contained striations. Sequencing of the COI and ND5 mitochondrial genes confirmed the identity of this parasite as Onchocerca lupi. Furthermore, the first sequence of the 12S mitochondrial gene is reported in this study.

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In the present study, fluorescent in situ hybridization (FISH) and monoclonal antibodies (MAbs) were evaluated for species-specific detection and viability determination of Giardia lamblia, Cryptosporidium parvum, and Cryptosporidium hominis in human fecal and water supply samples. A total of 50 fecal human samples positive for G. lamblia cysts, 38 positive for C. parvum, and 23 positive for C. hominis were studied. Also, 18 water supply samples positive for Giardia spp. and Cryptosporidium spp. by the United States Environmental Protection Agency (USEPA) Method 1623 were studied by FISH and fluorescein isothiocyanate (FITC)-conjugated MAbs. Eighteen percent of the fecal samples parasitologically positive for G. lamblia presented viable and nonviable cysts, and 5% of those positive for Cryptosporidium spp. presented viable and nonviable oocysts. Of the 18 water supply samples analyzed, 6 (33%) presented Giardia spp. viable and nonviable cysts and 2 (11%) presented viable and nonviable Cryptosporidium spp. oocysts. G. lamblia identification was confirmed by polymerase chain reaction (PCR) and sequencing of the beta-giardin gene in the fecal and water samples found positive by FISH and FITC-conjugated MAbs. C. parvum and Cryptosporidium muris were identified, by PCR and sequencing of the small subunit of ribosomal RNA gene, in seven and one water samples, respectively. Our results confirm that this technique enables simultaneous visualization, species-specific identification, and viability determination of the organisms present in human fecal and water supply samples.

The presence of Cryptosporidium parasites in mammals and reptiles kept at the Lisbon Zoo was investigated. A total of 274 stool samples were collected from 100 mammals and 29 reptiles. The species and genotype of the isolates identified by light microscopy were determined by nested PCR and sequence analysis of a fragment of the small subunit rRNA gene. Cryptosporidium oocysts were found in one black wildebeest (Connochaetes gnou), one Prairie bison (Bison bison bison) and in one Indian star tortoise (Geochelone elegans). The PCR and sequence analysis of these three isolates showed that those excreted by the Prairie bison were Cryptosporidium mouse genotype, those from the black wildebeest were from a new Cryptosporidium genotype and those infecting the Indian star tortoise were Cryptosporidium tortoise genotype. The present work reports a new Cryptosporidium genotype in a black wildebeest and the first finding of the Cryptosporidium mouse genotype in a ruminant.